Solving Exponential Word Problems

Solve this problem: When the apocalypse began, there were 5 zombies. Each day that number tripled. How many zombies would there be after a week (7 days)?

• 22

• 9,218

• 10,935

• 915

Write and exponential function for the following problem: Mrs. Madison starts the year off with 100 pencils. Each week, half of the pencils disappear. How many would be left after x weeks?

What would be the "a" value (initial value) for this problem? A local zoo has a population of 32 meerkats. They are doubling every 5 years. How many would there be in 10 years?

• 32

• 2

• 5

• 10

Solve the problem: Mrs. Madison has discovered she likes to crochet. She went out an bought 7 skeins of yarn to start her collection. That collection has doubled each month. How many skeins of yarn would she have after 6 months?

• 512 skeins

• 448 skeins

• 98 skeins

• 235,298 skeins

What would be the multiplier for this problem? Matt has the chicken pox. On day one, he counted that he had 10 spots. Each day that number quadruples. How many would he have after 3 days?

• 10

• 3

• 4

• 1/4

A population of 1200 bacteria is doubling each day for x days.

Rapunzel's hair grew 16% each week she was in the tower. If her hair was 20 inches long when she was placed in the tower, what is a model for the growth of Rapunzel's hair?

If Jack's Bean stalk grew 75% every hour and the bean stalk was 2 foot when he started watching it grow, what is a model for the growth of the bean stalk?

Write an equation that models the following situation: Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week. (HINT: Write out the equation on a separate piece of paper and hen simplify inside the parenthesis)

• y=6(0.14)^x

• y=6(1+14)^x

• y=6(1.14)^x

• y=6(0.86)^x

Is this exponential growth or decay?
y = 7(1.2)^x

• Growth, because of 7

• Decay, because of 1.2

• Growth because of 1.2

• Decay because of 7